Calibration of the mono-static stepped-frequency GPR with a Vivaldi UWB antenna

The mono-static stepped-frequency ground penetrating radar (GPR) with a Vivaldi ultra-wide band (UWB) antenna was used to non-destructive estimate the parameters (permittivity, conductivity and thickness) of each layer of a stratified subsurface medium. In this realization, a calibration procedure is necessary. This paper introduces the principle and the implementation of this calibration. The non-directive property of the Vivaldi antenna makes a challenge of the calibration of the system, because the measurement results are heavily disturbed by reflections from surrounding objects in air. However, after a suitable calibration, it can be used successfully in this radar configuration, and this was validated by the experiment.